Bearings are designed to support and position rotating shafts, to transfer loads between the rotating and stationary members, and to permit free rotation with a minimum of friction. A bearing is typically composed of rolling elements interposed between an outer and inner ring. Separators, sometimes called "retainers," are used to space the rolling elements from each other. These rolling elements are typically either ball bearings or roller bearings. Still, bearings may include no rolling members at all. The bearing may simply provide a low friction surface adjacent the shaft to control vibration.
The method of supplying the lubricant and the quantity of lubricant which is fed to the bearing will often be the greatest factor in establishing performance characteristics of the bearing. For example, if no lubricant is present, the journal and bearing will rub against each other in the dry state. If lubricant is present in even small quantities, the surfaces become contaminated by this material and the coefficient of friction between the surfaces will be reduced. If an abundance of lubricant is fed to the bearing so that there is an excess flowing out of the bearing, it is possible to provide a self-generating pressure film in the clearance space between the shaft and bearing. Such pressure film can be sufficient to sustain a considerable load and to keep the rubbing surfaces of the bearing separated.
A number of bearing designs also attempt to dampen vibrations from the rotating shaft. For example, U.S. Pat. No. 4,392,751 to Ida et al. discloses a damped bearing device which utilizes a fluid film between inclined surfaces. A bearing backup member can be moved in the axial direction along the inner surface of the housing by the turning of adjusting screws. However, no provision exists for the self-centering of the bearing block member since it is rigidly connected to the screws.
U.S. Pat. No. 4,023,868 to Miki features a damped bearing device in which the outer ring is axially slidable with respect to the case and rolling element so as to automatically adjust the bearing device to its initial pre-load condition. The O-ring can be positioned to allow for damping fluid to be between the upper surface of the outer ring and the lower surface of the case.
However, neither of these patents discloses a floating ring having an outer surface which is inclined to the same degree as the inner surface of the housing and which is allowed to float with respect to the cage and housing by way of specific positioning of flexible supports and fluid channels.
Therefore, a need exists for a damper which automatically compensates for changes in bearing position. Furthermore, this damper must be capable of maintaining adequate clearances between bearing elements, allowing those clearances to be filled with an oil film.